I have seen the Sony and Samsung 55" 4k TVs at Best Buy. They look great. I was able to see the Sony with some BluRay 2k content, and it looked good.

However, I read articles on CNET that say that 4k is not a factor at my seating distance.

{sound of screeching brakes, a car collision, and a hubcap rolling idly and then wobbling to a stop}

Can you post the Cnet article link? This has been a debate going on around here, and there are far too many people placing stock in the same carlton bale chart that gets circulated around.

User interface engineers: Always try to think in terms of putting in "un-do"s and not confirmation dialogs on every single question! Good grief! We're STILL doing this junior level newbie nonsense in 2015?????

(Here we go again) Round 425 of a fight that should never have existed.

User interface engineers: Always try to think in terms of putting in "un-do"s and not confirmation dialogs on every single question! Good grief! We're STILL doing this junior level newbie nonsense in 2015?????

When I look at the 4k TVs in the store they look great, even when I stand back. But I think part of that could be the fact they are feeding much higher quality content regardless of resolution than the standard store feed on the other sets.

I do think the resolution charts are not the entire picture so to speak. I know from working with typography and high DPI that your eye can notice subtle shading and contrast even though technically your eye can't resolve individual pixels. I'm no expert, I'm just going by what my own non 20-20 eyes do see.

When I look at the 4k TVs in the store they look great, even when I stand back. But I think part of that could be the fact they are feeding much higher quality content regardless of resolution than the standard store feed on the other sets.

It's conceivable that they're feeding it 4:4:4 and otherwise uncompressed imaging, but I find that unlikely. 4:2:0 is perfectly fine, and I think you're likely seeing quality that appears as it would from a 4K blu-ray.

Quote:

I do think the resolution charts are not the entire picture so to speak. I know from working with typography and high DPI that your eye can notice subtle shading and contrast even though technically your eye can't resolve individual pixels. I'm no expert, I'm just going by what my own non 20-20 eyes do see.

I've stared and stared at the 4K X900 at BB/Mag and because my couch is more than 12 feet back from my own set I tested that as well. There's no way I'm not seeing 4K effects.

I also have a pre-press / printed graphics background and yes, I also know not to base things on acuity charts. But with TVs the charts are a far less appropriate metric because motion is now involved (as opposed to typography). And your eye/brain neurology can detect edges in apparently insane ways: that's it's job in fact. Your eye is not a CCD array. One of the oddball examples I've given in the past has to do with a spiderweb strand some 20 feet away. You can often not see it at all, even if you're staring right at it, until it moves. In fact, your eye undergoes saccadic motion even with stationary things to further this phenomenon, and when it's coupled with a change against a reference background as well (such as with video), you really have an amazing ability to see a difference.

User interface engineers: Always try to think in terms of putting in "un-do"s and not confirmation dialogs on every single question! Good grief! We're STILL doing this junior level newbie nonsense in 2015?????

I've stared and stared at the 4K X900 at BB/Mag and because my couch is more than 12 feet back from my own set I tested that as well. There's no way I'm not seeing 4K effects.

I also have a pre-press / printed graphics background and yes, I also know not to base things on acuity charts. But with TVs the charts are a far less appropriate metric because motion is now involved (as opposed to typography). And your eye/brain neurology can detect edges in apparently insane ways: that's it's job in fact. Your eye is not a CCD array. One of the oddball examples I've given in the past has to do with a spiderweb strand some 20 feet away. You can often not see it at all, even if you're staring right at it, until it moves. In fact, your eye undergoes saccadic motion even with stationary things to further this phenomenon, and when it's coupled with a change against a reference background as well (such as with video), you really have an amazing ability to see a difference.

We see *less* resolution on a screen for Items in motion than for static items. The reason is motion blur during capture and judder during display. The eye's resolving power for items in motion is also the same as for static items, this is because nothing is static on the retina anyway (because of the saccades you mention). I would also point out that individual display pixels aren't moving anyway, that is unless you put your TV on casters and push it across your floor.

But, there is an important factor from motion in determining the pixels needed for a display with "invisible" pixels. By invisible, I mean one where you can't tell that it is made up of individual pixels. That factor is that artifacts that move are far more visible than stationary artifacts. So, while some aliasing is not too objectionable in a static image, any aliasing in a moving image is distracting and ugly. Now avoiding aliasing is at odds with preserving detail right up to the pixel spacing, so having extra pixels beyond what a person can strictly see is helpful to simultaneously avoid artifacts and have sharp details at the visible limit. How much extra you need depends on how the anti-aliasing is performed. If first you capture a very high resolution image (say with a Red Epic-Dragon camera), then digitally down-sample it, you can retain more detail without artifacts than if you directly capture at the display resolution. (The best Blu-Ray discs are generated from movies captured originally with more than 2K resolution.)

It is simple to determine how much resolution you need if you own a set today: Simply change your viewing distance to check the effect of different numbers of pixels per angle of view. I think a reasonable rule of thumb is to use a pixel spacing just finer than the high contrast resolution limit for your vision. At that spacing, with natural images (not computer generated), the pixels will be invisible for all but the highest contrast edges. This is the value used in the Sony paper justifying 4k theater projection. Sony used 20:20 vision which yields the following ratios for viewing distance to image height based on the number of pixels vertically:

I've stared and stared at the 4K X900 at BB/Mag and because my couch is more than 12 feet back from my own set I tested that as well. There's no way I'm not seeing 4K effects.

I also have a pre-press / printed graphics background and yes, I also know not to base things on acuity charts. But with TVs the charts are a far less appropriate metric because motion is now involved (as opposed to typography). And your eye/brain neurology can detect edges in apparently insane ways: that's it's job in fact. Your eye is not a CCD array. One of the oddball examples I've given in the past has to do with a spiderweb strand some 20 feet away. You can often not see it at all, even if you're staring right at it, until it moves. In fact, your eye undergoes saccadic motion even with stationary things to further this phenomenon, and when it's coupled with a change against a reference background as well (such as with video), you really have an amazing ability to see a difference.

We see *less* resolution on a screen for Items in motion than for static items. The reason is motion blur during capture and judder during display. The eye's resolving power for items in motion is also the same as for static items, this is because nothing is static on the retina anyway (because of the saccades you mention).

I hit the thumbs-up for your post, but you have part of this backwards. First, I'm not talking about quickly moving (across screen space) objects, that's a different effect entirely involving a different strobe. Second, IRL the eyes resolving power is absolutely not the same for static items as with items in motion because the saccadic motion by itself does not change the background with respect to the object. Having the object in motion does, and doing so causes a stronger set of edges to form. In fact, the object doesn't even need to be a continuous line (nor even moving with or without saccades): phantom edges appear (illusory contours), but this is amplified by foreground over background motion. There's a great effect that is related to illusory contour gestalt that involves a checkerboard pattern being moved over another checkerboard pattern resulting in a human seeing the contours of a rabbit form. The illusory contours even on angle are smooth and non-discrete. I can't seem to find it online and am looking. You've probably seen it in a science museum; I know I have.

You are correct that in a display you have two smears going on: the blur inherent in the capture to the sensor during the open shutter, and the resulting sample and hold smear against the retina as your eye attempts to follow the motion. But when the shutter is fast enough, and the screen is similarly employing a pulse technique, the apparent resolution due to motion is very high.

User interface engineers: Always try to think in terms of putting in "un-do"s and not confirmation dialogs on every single question! Good grief! We're STILL doing this junior level newbie nonsense in 2015?????

I think many people can just discern 20:15 details even if they can't identify text at that scale.

This is a good bit of information, but why 20:15? I have (now) L:20/20 & R:20/25 vision can discern differences in objects far down the eye chart without identifying the actual glyphs. I can "see" the difference I can't "see". Where is the line drawn for details? It's not a discrete can or can't calculation, is it?

User interface engineers: Always try to think in terms of putting in "un-do"s and not confirmation dialogs on every single question! Good grief! We're STILL doing this junior level newbie nonsense in 2015?????

No, you have part of this backwards. First, I'm not talking about quickly moving (across screen space) objects, that's a different effect entirely involving a different strobe. Second, IRL the eyes resolving power is absolutely not the same for static items as with items in motion because the saccadic motion by itself does not change the background with respect to the object. Having the object in motion does, and doing so causes a stronger set of edges to form. In fact, the object doesn't even need to be a continuous line (nor even moving with or without saccades): phantom edges appear (illusory contours), but this is amplified by foreground over background motion. There's a great effect that is related to illusory contour gestalt that involves a checkerboard pattern being moved over another checkerboard pattern resulting in a human seeing the contours of a rabbit form. The illusory contours even on angle are smooth and non-discrete. I can't seem to find it online and am looking. You've probably seen it in a science museum; I know I have.

You are correct that in a display you have two smears going on: the blur inherent in the capture to the sensor during the open shutter, and the resulting sample and hold smear against the retina as your eye attempts to follow the motion. But when the shutter is fast enough, and the screen is similarly employing a pulse technique, the apparent resolution due to motion is very high.

Most of the effects that you are referring to like phantom edges are caused by artifacts present from aliasing (Note: moire or aliasing also occurs when moving a physical aperture grid in front of an object). When there is zero aliasing these artifacts disappear. Very careful processing is required to both preserve details at the pixel limit and avoid all aliasing artifacts, it is easy to find demos that fail to do this. One thing that the diversity of sampling caused by motion does add is an apparent *increase* in the effective resolution of a sensor. Pixels can fall in different places on an object as it moves. This means that for moving objects, a 4k camera can behave more like an 8K camera by later images sampling the locations between the pixels in the earlier images. This would only be useful if the image contained details for 8K sampling- which it shouldn't for a 4K camera with an effective anti-aliasing filter. Anyway, I already mentioned that it is best to start with a high res image and down-sample to the display resolution.

The shape of the displayed pixels does matter when past the resolution limit: for full color pixels an octagonal shape without gaps between pixels is better than a square. For pixels composed of sub-pixels for each color, it is possible to upsample to the sub-pixel spacing and perform a sub-pixel drive scheme similar to Microsoft's clear-type.

This is a good bit of information, but why 20:15? I have (now) L:20/20 & R:20/25 vision can discern differences in objects far down the eye chart without identifying the actual glyphs. I can "see" the difference I can't "see". Where is the line drawn for details? It's not a discrete can or can't calculation, is it?

No it is not a fixed limit, it depends on contrast. Remember that eye charts are presented as maximum contrast hard black/white edges that don't always occur in natural images. So, you might not need the same resolution for a jungle movie as for a movie with lots of urban landscapes.

I based my 20:15 value partly on what I feel the limit is for the image height to distance ratio where I can no longer gain content viewing my 1080p S4 smartphone. Note: I am near sighted (-4.5 diopter), so I can focus to very close objects. I also experimented with my 50" television.

No it is not a fixed limit, it depends on contrast. Remember that eye charts are presented as maximum contrast hard black/white edges that don't always occur in natural images. So, you might not need the same resolution for a jungle movie as for a movie with lots of urban landscapes.

I based my 20:15 value partly on what I feel the limit is for the image height to distance ratio where I can no longer gain content viewing my 1080p S4 smartphone. Note: I am near sighted (-4.5 diopter), so I can focus to very close objects. I also experimented with my 50" television.

A better test image than an eye chart would be a camera resolution test chart with frequency sweeps or the multi-frequency blocks like the Air Force chart. I should try my test again displaying resolution charts on my phone and TV.

Interesting. Excuse my thickness, but what formula are you using to determine the maximum screen size based on 20:15 vision? I assume it involves an algebraic expression using distance/image-height ratio and number of lines, but I am having trouble duplicating your results for 10 feet.

Interesting. Excuse my thickness, but what formula are you using to determine the maximum screen size based on 20:15 vision? I assume it involves an algebraic expression using distance/image-height ratio and number of lines, but I am having trouble duplicating your results for 10 feet.

The phantom edges I was talking about had noting to do with aliasing. The effects I was referring to occur in real life as well.

User interface engineers: Always try to think in terms of putting in "un-do"s and not confirmation dialogs on every single question! Good grief! We're STILL doing this junior level newbie nonsense in 2015?????

The phantom edges I was talking about had noting to do with aliasing. The effects I was referring to occur in real life as well.

As does moire aka aliasing. I think you missed out on reading the placard by the science museum display.

Placing a screen or grid (or in fact any occluding object) in front of a background causes aliasing just the same as placing an image on a pixel grid. The real world aliased detail is now at a new, lower frequency and so can be perceived by the eye or recorded by a sensor with a pixel count based on this new low frequency.

Just checking in here. As the OP I have been following the thread with great interest and diligently reading the information provided. I do not follow all the math and science, but very much appreciate the discussion.

For my personal situation, it sounds like the benefit of 4k at my primary seating location of 12 feet would be marginal. At my closer location of 9 feet there could be some benefit, though the 9 foot spot is off to the side, so there is the loss from LCD viewing angles. Combine the science with my need to keep my current 1080p devices running for a number of years has me leaning towards sticking with 1080p.

Part of me wants to rush out and get a TV (discipline!) but I will continue to read with great interest how 4k and upconversion shakes out over the next couple of months.

On a bit of a tangent, I think if manufacturers of 4k BluRay players implement the dual HDMI output like the Sony 4k media player they will get much quicker adoption. I'm sure there are plenty of folks like me that are perfectly happy with their AV receiver and don't relish having to upgrade that piece as well. Having 1 HDMI output go to the 4k TV for video and 1 HDMI output go to the receiver for audio is a great compromise for the early adopters.

1. Get rid of the cabinet - you shouldn't limit yourself or your guests to a 55" TV unless you are 4' or less from the screen.

2. Ignore "standard" distance recommendations - LOOK for yourself - See step 3 for the correct way to size a TV.

3. Take a piece of painters tape or a post it note and put it in the bottom corner of where you think you'd like your TV. Now put another piece on a diagonal about 80" away - now sit back in your seat - can you see both corners without moving your eyes? Close one eye - can you still see both pieces of tape? Voila the "experts" (e.g. consumer reports) are idiots or are wearing horse blinders. The content of what you are watching is almost always in the center anyways - the rest is to help you feel enveloped by the environment.

4. Buy a 65" 1080p Samsung or Panasonic plasma for now and plan on moving it to your bedroom in 3-4 years once the 75" 4K OLEDs get to a reasonable price. And yes, you will notice the 4K improvement unless you pretend you don't - like people who buy Milwaukee's best and say all beer tastes alike. When you were at the store and saw the 4K I bet you were 12' or less when you noticed it. The current 4K Sonys have a nice picture but dreadful motion.

My opinion only and I know it's not what you are asking but I have seen these UHD sets and sure they look good but from I can tell it is not mind boggling better at this point and time. Content?? Where? Up convert ? Ugh just like the later days of DVD ?

That distance seems a bit far but I know some will say okay. I moved my 55 into my bedroom when I went 70 in living room and I am in a small bedroom and set is 8 or 9 feet away and it is just fine.

Everyone wants the latest when they buy but to me this is stop-gap time. UHD and OLED just not what it can or will be in a couple of years.

If it were me I would be looking at 65 Plasma or up to 70 LCD. The enjoyment 70 has brought me for movies out ways any 55 UHD or OLED could even hope to do.

65 n up and a great Bluray is about as good as gets right now. It will get you off the merry-go-round and wait it out for things to get bigger, better and cheaper over the next couple of years.

55 is a perfect bedroom tv these days IMO of course. Not for a primary viewing room.

Agreed time to let go of working tv's around a cabinet. But not my furniture so I will shut-up but been there done that!

I appreciate the sentiments about the cabinet and size of the TV. This TV is for my living room which has specific furniture fitting in with my 1920 Spanish Colonial Revival house. Everyone makes choices and compromises. I love my cabinet and don't want the TV to be visible in the room while I'm not watching TV. This is my choice. Given my self-imposed constraints, it sounds like 4k is not there for me yet. That's fine.

I have had Plasmas (and tried a Samsung F8500) , and I love them, but they did not work in my living room. My living room has large arched windows which are impractical to completely cover. Lots of light. For my situation, I need the brightness of LCD/LED.

Thanks for all the feedback, I continue to read about this with great interest.

Marcus

PS I like quality micro-brew beer, but I also like macro-brewed American light beer. Each have their place.